1. Field of the Invention
The present invention relates to a multi-band orthogonal frequency division multiplexing ultra wide-band (MB-OFDM UWB) system, and more particularly, to an apparatus and a method for receiving signal for extent of timing synchronization in MB-OFDM UWB System which is capable of securing the stable receiving performance in system environment with severe frequency offset.
This work was supported by the IT R&D program of MIC/IITA. [2006-S-071-02, A Development of high speed multimedia transmission UWB Solution]
2. Description of the Related Art
Timing synchronization algorithm in packet communication system applied of previous orthogonal frequency division multiplexing (OFDM) system used the method to locate the peak of correlation value at receiving-end after forming preamble using the sequence excellent in correlation property. Timing synchronization algorithm using sequence excellent in correlation property was mainly applied to IEEE 802.11a system.
Timing synchronization algorithm is finding the boundary of short training symbol and long training symbol section by executing the cross-correlation and peak detection using short training symbol or long training symbol as its standard signal. In paper ‘Optimum frame and frequency synchronization for OFDM systems’ published in Consumer Electronics, 2001, method to find the frame synchronization through correlation between the matched filter coefficient at receiving-end and received short sequence using the IEEE 802.11a OFDM preamble structure was disclosed. In the paper ‘Robust timing synchronization for OFDM based wireless LAN system’ presented in TENCON 2003, Conference, specific operation to acquire frame synchronization using the average of single short symbol was disclosed.
These timing synchronization technologies are to effectively implement the timing synchronization algorithm using sequence excellent in correlation property of which do not consider the fact that sampling may begin at random location even if it is the same sample section generated during the conversion of analogue signal to digital signal that may occur in analog to digital converter (ADC) and FFT window transition based on sampling clock offset. Namely, there is a problem for previous algorithms that uses the phase difference between same samples of two OFDM symbols among received preamble symbols in that error may occur with dislocation of sample location with the FFT window shift between the two OFDM symbols in comparison by sampling clock offset of sending and receiving-end.